Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 301)

NOTE
If you change the 802.1W state of the primary port in a trunk group, the change affects all ports in that
trunk group.
To disable or enable 802.1W on an individual port, enter commands such as the following.
device(config)#interface e 1
device(config-if-e1000-1)#no spanning-tree
Syntax: [no] spanning-tree
Changing 802.1W bridge parameters
When you make changes to 802.1W bridge parameters, the changes are applied to individual ports on
the bridge. To change 802.1W bridge parameters, use the following methods.
To designate a priority for a bridge, enter a command such as the following.
device(config)#spanning-tree 802-1w priority 10
The command in this example changes the priority on a device on which you have not configured port-
based VLANs. The change applies to the default VLAN. If you have configured a port-based VLAN on
the device, you can configure the parameters only at the configuration level for individual VLANs. Enter
commands such as the following.
device(config)#vlan 20
device(config-vlan-20)#spanning-tree 802-1w priority 0
To make this change in the default VLAN, enter the following commands.
device(config)#vlan 1
device(config-vlan-1)#spanning-tree 802-1w priority 0
Syntax: spanning-tree 802-1w [ forward-delay value] | [hello-time value] | [max-age time] | [force-
version value] | [priority value]
The forward-delay value parameter specifies how long a port waits before it forwards an RST BPDU
after a topology change. This can be a value from 4 - 30 seconds. The default is 15 seconds.
The hello-time value parameter specifies the interval between two hello packets. This parameter can
have a value from 1 - 10 seconds. The default is 2 seconds.
The max-age value parameter specifies the amount of time the device waits to receive a hello packet
before it initiates a topology change. You can specify a value from 6 - 40 seconds. The default is 20
seconds.
The value of max-age must be greater than the value of forward-delay to ensure that the downstream
bridges do not age out faster than the upstream bridges (those bridges that are closer to the root
bridge).
The force-version value parameter forces the bridge to send BPDUs in a specific format. You can
specify one of the following values:
• 0 - The STP compatibility mode. Only STP (or legacy) BPDUs will be sent.
• 2 - The default. RST BPDUs will be sent unless a legacy bridge is detected. If a legacy bridge is
detected, STP BPDUs will be sent instead.
The default is 2.
Spanning Tree Protocol
FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide 301
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